Robin Williams' wife confirmed he was battling the early stages of Parkinson's disease before he tragically took his own life Aug. 11, but newly released autopsy details reveal that he was also suffering from a form of dementia.

Per Today, the main conclusion in the coroner's report was "...findings in this case support the diagnosis of of diffuse Lewy body dementia." This disease can cause visual hallucinations which can be frightening and cause people to act out, confirmed Dr. James Galvin, professor of neurology at New York University.

It's also not uncommon for Lewy body dementia to make depression worse. As Dr. Galvin explained, "For many people who suffer both from depression and the dementia, the depression will make the memory symptoms worse."

Friends of the late star told Today Williams' family did not know the Oscar winner was suffering from that disease, but nothing in the report was surprising to them--it all seemed to fit with what they'd observed.

Lewy body is the second most common form of dementia after Alzheimer's and affects an estimated 1.3 million Americans. Another high profile star, Casey Kasem, passed away earlier this year after suffering from the disease, his family said.

"Not many good things can come out of someone passing," said Dr. Galvin, "but one thing that can come of it is to raise awareness of a disease for which people really don't understand."

Sources close to the Williams' family told Today they found the autopsy report "illuminating," and they hope this news "helps stimulate public conversation so that if others need help with Lewy body, maybe they'll be motivated now to get that help."